The card scheme uses its rules to transfer card transaction information from the receiving bank to the issuing bank (from the merchant to the consumer). It then passes the payment to the acquirer to confirm the payment.

Credit and debit card schemes work with four parties. Together, these four teams create an open-loop system that allows customers to purchase items or services from merchants, allowing the bank to do all the work on their behalf without interruption.

Cardholder:
Buyer. They hold a debit or credit card issued by their bank.

Card issuer:
It provides debit or credit cards to its eligible customers from the card scheme. Issuers are banks (and other qualified institutions). Even when the card is branded (such as an airline loyalty card), no bank or financial institution supports the card.

Merchant:
A retailer or a business that sells goods or services to a cardholder.

Acquirer:
Does the company provide a merchant service contract to the merchant and process card transactions on their behalf?

Although these are the four primary players, there are some intermediaries that facilitate transactions, including payment gateways and payment processors.

The function of card schemes is to make transactions as easy as possible for the four players in the loop. When a transaction goes smoothly, customers spend more: all four players win.